I'm finding 2 conflicting answers for maximum value that pi(n)/(n/ln(n)) can output, where pi(n) is the prime counting function and ln(n) is the natural log.

An inequality by Chebyshev says that the maximum is less than 9/8 (can be found at Prime Number Theorem -- from Wolfram MathWorld). However, setting n=13 we get pi(13)/(13/ln(13))≈1.255 (type it in to WolframAlpha to see for yourself) which is greater than 9/8.

So my question is, is something about Chebyshev's statement wrong (I doubt it), or am I misunderstanding something, and if so, what?

Jul 13th 2010, 08:50 AM

chiph588@

Quote:

Originally Posted by blindConjecture

I'm finding 2 conflicting answers for maximum value that pi(n)/(n/ln(n)) can output, where pi(n) is the prime counting function and ln(n) is the natural log.

An inequality by Chebyshev says that the maximum is less than 9/8 (can be found at Prime Number Theorem -- from Wolfram MathWorld). However, setting n=13 we get pi(13)/(13/ln(13))≈1.255 (type it in to WolframAlpha to see for yourself) which is greater than 9/8.

So my question is, is something about Chebyshev's statement wrong (I doubt it), or am I misunderstanding something, and if so, what?

I assume they meant to say for large enough , like they do for the next inequality.

Jul 13th 2010, 09:31 AM

blindConjecture

Yeah, after reading some more of that page I came to the conclusion. Thanks.